That's exactly my point. At the end of the day, no lock is safe from an angle grinder. I just want my lock to be a deterrent to thieves and keep my bike from being stolen. I've ordered this lock as a kit with the mount and the larger cable to protect my wheels. This version doesn't have any reviews but I assume it works exactly the same. I don't have a brilliant bike, but its a nice 10-20 year old Raleigh in brilliant condition which I paid £45 for and I want to keep it safe. I promised I wouldn't get attached to it but it's a little late for that, but I wont be leaving it any longer than an hour in a busy location, so it should be okay. Thank you! I'm glad yours is doing the job!
Kryptonite do very good U locks but they are a bit expensive, there is a private label U lock that I use, I'll link it, that has a 16mm shackle and it usually costs less than $25. ABUS is a good brand but again, expensive. Basically you're looking for something with the thickest shackle for the lowest cost with no gimmicks. Same with a chain but now the lock doesn't matter that much, you can replace it with either a disc lock (not a round padlock, a lock for disc brake rotors) or a good padlock (if you get a padlock get one with a shielded shackle, such that when it is in use it would be difficult to access the shackle). Squire do some thick chains but they are pretty expensive, onguard are a bit cheaper but the chains are not the thickest.
Links:
The private label U lock (I couldn't find a US link) https://www.amazon.co.uk/Burg-W%C3%A4chter-1600HB-Bicycle-Large-2-1M/dp/B09BNT3DQ2/ref=mp_s_a_1_6?keywords=burg+w%C3%A4chter+D+lock&link_code=qs&qid=1661603735&sourceid=Mozilla-search&sr=8-6
Example of the type of padlock that is best for chains https://www.amazon.com/Vulcan-Premium-Hardened-Security-Chain/dp/B076DPMRFF/ref=mp_s_a_1_45?crid=J41I5MK6904B&keywords=Disc+Wheel+lock&qid=1661603502&sprefix=disc+wheel+lock%2Caps%2C335&sr=8-45
I couldn't find a disc lock of the right kind, basically you want one that does NOT have a bit that goes around the rotor, you want one that locks a kind of mushroom shaped shackle to itself through the rotor.